Screen contrast

cristianm · 07-01-2010, 02:16 AM

Boox's screen contrast is a bit lower than Kobo's, meaning that the background is perhaps up to 2% darker on a scale from 0% to 100%. Not much, and very readable still, but clearly noticeable.
Knowing there is only one manufacturer for the Vizplex screen, I wonder if any technical explanation is available. Since the screen is placed in front of the Wacom touchscreen, shouldn't be any difference.
... any technical savvy around?

Delta Tango · 07-01-2010, 12:13 PM

It's probable due to the protective material placed over the actual display.

Dulin's Books · 07-01-2010, 04:11 PM

are you using the same font in each? same book file?

cristianm · 07-02-2010, 08:19 AM

I used the same file (in fact I have the same book collection on both devices).

The difference is still there when I shut them down, aka blank screens. I've printed a rough calibration paper page with gray stripes going from levels of 1% to 14% grayscale in 1% increment, and I would say Boox has a background of about 9% level of gray and Kobo is closer to 7% (measured in natural light in a windowed room, otherwise these values may be lower - for example in direct sunlight).

There's absolutely no criticism in this, I'm perfectly happy with both devices ... just looking for a tehnical explanation if any.

Dulin's Books · 07-02-2010, 10:43 AM

the reason for the difference would be something in the code that drives the display. I posted in another thread that if you read the Boox with full refresh off you get a whiter area around the letters than the normal backround. So their blank state is not as "white" as it could be.

Purple Lady · 07-02-2010, 06:52 PM

I think the contrast is a bit lower in the Boox because the text is dark gray, not black. Look at the status bar to see what black really is.

cristianm · 07-11-2010, 05:05 AM

For those interested to see the screens of Boox and Kobo side by side I took two pictures in the same conditions, loaded into Photoshop and converted them to grayscale.

If you open the Info Window in Photoshop and hover the mouse inside the black rectangle added to each picture, you see grayscale ranging from 28 to 32% for Boox, and from 23 to 27% for Kobo.

I think mr. Dulin is right, and I also found that minor differences may occur even in the manufacturing process of different Vizplex batches.

07-01-2010, 02:16 AM	#1
cristianm Member Posts: 12 Karma: 10 Join Date: May 2010 Device: Boox 60, Kindle 3, PRS-650	Screen contrast Boox's screen contrast is a bit lower than Kobo's, meaning that the background is perhaps up to 2% darker on a scale from 0% to 100%. Not much, and very readable still, but clearly noticeable. Knowing there is only one manufacturer for the Vizplex screen, I wonder if any technical explanation is available. Since the screen is placed in front of the Wacom touchscreen, shouldn't be any difference. ... any technical savvy around?

07-02-2010, 08:19 AM	#4
cristianm Member Posts: 12 Karma: 10 Join Date: May 2010 Device: Boox 60, Kindle 3, PRS-650	I used the same file (in fact I have the same book collection on both devices). The difference is still there when I shut them down, aka blank screens. I've printed a rough calibration paper page with gray stripes going from levels of 1% to 14% grayscale in 1% increment, and I would say Boox has a background of about 9% level of gray and Kobo is closer to 7% (measured in natural light in a windowed room, otherwise these values may be lower - for example in direct sunlight). There's absolutely no criticism in this, I'm perfectly happy with both devices ... just looking for a tehnical explanation if any. Last edited by cristianm; 07-02-2010 at 09:00 AM. Reason: Measurement environment

07-11-2010, 05:05 AM	#7
cristianm Member Posts: 12 Karma: 10 Join Date: May 2010 Device: Boox 60, Kindle 3, PRS-650	For those interested to see the screens of Boox and Kobo side by side I took two pictures in the same conditions, loaded into Photoshop and converted them to grayscale. If you open the Info Window in Photoshop and hover the mouse inside the black rectangle added to each picture, you see grayscale ranging from 28 to 32% for Boox, and from 23 to 27% for Kobo. I think mr. Dulin is right, and I also found that minor differences may occur even in the manufacturing process of different Vizplex batches. Attached Thumbnails

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Screen Contrast - Nook vs K3?	ManosHandsOfFate	Which one should I buy?	2	09-01-2010 07:57 AM
Screen Contrast	DrDk	Astak EZReader	12	03-06-2010 09:27 AM
Screen contrast	DrDk	Ectaco jetBook	3	03-04-2010 11:11 PM
Got my reader today - Screen contrast	devastat	Sony Reader	16	07-30-2009 07:25 PM
I guess it boils down to Screen contrast	Rocketime	Sony Reader	2	10-11-2007 12:12 PM

07-01-2010, 12:13 PM	#2
Delta Tango Groupie Posts: 161 Karma: 20000 Join Date: Mar 2010 Location: Zagreb, Croatia Device: Onyx Boox	It's probable due to the protective material placed over the actual display.

07-01-2010, 04:11 PM	#3
Dulin's Books Wizard Posts: 2,806 Karma: 13500000 Join Date: Nov 2009 Location: Portland, OR Device: Boox PB360 etc etc etc	are you using the same font in each? same book file?

07-02-2010, 10:43 AM	#5
Dulin's Books Wizard Posts: 2,806 Karma: 13500000 Join Date: Nov 2009 Location: Portland, OR Device: Boox PB360 etc etc etc	the reason for the difference would be something in the code that drives the display. I posted in another thread that if you read the Boox with full refresh off you get a whiter area around the letters than the normal backround. So their blank state is not as "white" as it could be.

07-02-2010, 06:52 PM	#6
Purple Lady Grand Sorcerer Posts: 5,698 Karma: 16542228 Join Date: Feb 2010 Location: Pennsylvania Device: Huawei MediaPad M5, LG V30, Boyue T80S, Nexus 7 LTE, K3 3G, Fire HD8	I think the contrast is a bit lower in the Boox because the text is dark gray, not black. Look at the status bar to see what black really is.

Advert

Advert